1. Field of the Invention
The present invention relates to an apparatus for producing thin boards by chipless cutting of the boards from a log or a squared timber on one or both opposite sides of the squared timber.
2. Description of the Prior Art
It is necessary in chipless separation processes to achieve adequate surface quality in the cut boards. This is rendered very difficult because of the tendency of the wood to split and tear. An apparatus has been proposed which has a cutter blade on one side and on the opposite side has a contact pressure band with pressure rollers. In the apparatus, the contact pressure band with the pressure rollers is used both for applying the contact pressure forces and also the forces required to feed the wood. Since, however, the pressure needed to achieve a good quality cut is not necessarily the same as the pressure which is needed to apply the required feed forces toward the cutter blade or the set of cutter blades, contact pressure forces cannot be choosen on the basis of the requirements for the cutting quality alone.
Opposing cutter blade arrangements are known from DE-OS 33 43 294 where feed elements are provided separate from the contact pressure system, since no feed can be achieved by the contact pressure of the opposing cutter blade set. The feed rollers which have been used to the present, which are essentially arranged on swinging arms in order to accommodate logs of varying thicknesses, did not offer the possibility of applying great clamping forces for the substantial feed forces required for chipless-cutting separation without the pressure conditions of the wood between the cutter blade sets being changed with respect to forces at the same time, i.e., symmetrically high clamping forces are not possible regardless of the particular position of the log or the squared timber at any one time.